Preheat your oven to 350°F.
In a stand mixer or with a hand mixer, cream together the butter and sugars on medium-high speed for 1 minute until well combined.
Add the molasses and egg, and mix on medium-high speed for another minute until well combined.
Add the dry ingredients and mix on low speed until just combined.
Spread the batter into an 8x8-inch metal pan lined with parchment paper.
Bake for about 30 minutes, until the center is soft and the edges are chewy.
Optionally, top with white chocolate chips after baking. They will melt beautifully into the blondies.